I have always had sand in my tanks, except my current one.
It was never planned, i changed over tanks and never got around to putting sand in, it is so much easier to maintain, i have loads of nice flow all around and no detrius build up.
I prefer the look of sand but all my tanks have been bare bottomed for the last couple of years (wasn't planned, just never got round to it). They are a lot easier to maintain and the bottom ends up getting covered in coraline anyway.